Adjustable reamer



. E. E. LARSON.

ADJUSTABLE BEAMER.

APPLICATION FILED DEc. I3, I9I9.

Patented Jun@ 22, 1920.

broken taps as above mentioned in that if EDWARD E. LARSON, 0F THOMPSON, IOWA.

ADJUSTABLE BEAMER.

Specification of Letters Patent.

Patented June 22, 1920.

Application led December 13, 1919.` Serial No. 344,531.

Beamers, of which the following is a specication.

This invention relates to improvements in adjustable reamers.

An important obj ect of the invention is to provide a device of the above mentioned character, which is readily and cheaply constructed and in which the cost of maintenance is greatly reduced.

In adjustable reamers and in many of the tools used/in milling machines, longitudinally adjustable blades are provided which when placed in the proper position are held in such position .by a wedge. Heretofore it has been the practice to use a wedging screw having threaded engagement with the body-of the tool and engaging against a resilient portion which is forced, by the driving in of the wedging screw, into engagement with the cutter to hold the same in place. These screws often break or the threads, either in the body of the tool or upon the screw, strip. This occasions much delay in that new threads must be formed in the body of thel tool in the first instance, and in the second instance the threads upon the body of the tool must be thoroughly cleaned and a new screw provided. Then again these screws often break off while engaging in the threads, andin forming the threads a tap is often broken off in the body of the metal. In the firstinstance the hole must be rebored and retapped for the reception of the new screw, and in the second instance it often becomes necessary to throw away the body of the tool containing the broken tap. Each of these difficulties I have eliminated by forming in the body of the tool instead of a threaded 'aperture a straight bore which receives a cylindrical bur. This bur is provided with screw threads adapted to receive the threaded portion of the tapered screw. Means are provided for releasably holding these burs within the bores. In event a screw is broken or the threads of the bur or screw strip the bur is simply removed from the bore and a new one inserted. This device also eliminates the waste occasioned by a tap breaks within the bur the bur may be discarded with but a slight monetary loss.

Other objects and advantages of the invention will be apparent through the following description.

In the accompanying drawings wherein for the purpose of illustration is shown a preferred embodiment of my invention and wherein like numerals designate like parts throughout.

Figure 1 is a plan view of a reamer constructed in accordance with my invention and wherein` like. numerals designate like parts throughout.

Fig. 2 is an enlarged sectional view showing the tapered adjustable key.

Fig. 3 is a section taken on the line 3 3 of Fig. 1, and

Fig 4 is a detail view of the bur holding pin.

Referring now more particularly to the drawings the numeral 10 indicates the body of a reamer or the like. This body portion is provided with spaced radial slots 11 having one side thereof tapered as at 12. Seated within the tapered portion of the slots 11 are tapered keys 13 which are provided upon one side thereof with longitudinal serrations 14.

Provided with longitudinal serrations 15 are cutter members 16. It will be obvious that rough adjustments of the cutter members 16 may be had by shifting the cutter member to advance it one serration or conversely to withdraw it one serration. When a finer adjustment is desired( this may be had by driving the wedge keys 13 in or out as may be desired the wedge keys being provided with a scale 13 by which the amount of adjustment may be observed and governed.

The numeral 17 designates a screw mounted in the cutter membersv to prevent slipping thereof to a position in which any of cutting edges are out of line. It will be obvious that this result may be attained in various ways and I accordingly do not limit myself to the use of a screw.

Provided adjacent the side of each of the slots 11 in which the cutter members 16 inner ends with bores 19. These slots form may be provided as desired. Mounted within the bores 22 are cylindrical members 23 having a solid portion 24 provided with a threaded aperture adapted to receive the threaded portion of the screw 22. These cylindrical members are also provided with a transverse slot 25 adapted to receive a pin 26 which is inserted through the bore 19. The pin 26 is provided upon one side thereof with a hump 27 which engages againstpthe side of the bore to prevent accidental slipping of the pin from the bore.

It will be obvious that in event of breakage the cylindrical members are readily removable from and replaceable in the bores 22 and that such removal and replacement can be made without any undue loss of time. It is to be understood that I do not limit the useI of these bores for receiving wedging screws to the form of reamer shown as they may be advantageously used in any place where a screw is used that is subjected to a larger amount of strain and usage andtherefore liable to be frequently broken.

What I claim is:

l. In a reamer, a body portion provided with spaced radial slots, tapered keys disposed within said slots and provided upon one side thereof with serrations, cutter members arranged within said slots and provided with serrations adapted to coact with the serrations in said keys and means for locking said cutter members in position. Y A

2. In a reamer, a body portion provided with spaced radial slots, tapered keys disposed within said slots and provided upon one side thereof with longitudinal serrations and upon the other with a scale, cutter mem` bers arrangedl within said slots and provided with longitudinal serrations adapted to coact with the serrationsin said keys, and

p means for locking said cutter members in position. Y v

3. `In a reamer, a body portion provided Iwith spaced radial slots, cutter members arranged within said slots, and means for locking said cutter members in position7 embodying bores formed adjacent to one side of and longitudinally parallel with said l slots, other slots formed in said 'body portion and communicating with said bores thereby forming intermediate said body portion and said first named slots, flexible strips, cylindrical members releasably held Within bores formed partially in said flexible strips and partially in said body portion, means disposed within said first named bore for releasably engaging said cylindrical members and retaining them in position bers arranged within said slots and provided with serrations adapted to coact with the serrations in said keys, and means for lock- -ing saidcutter members in position, em-

bodying 'flexible strips arranged between the body portion and said cutter members, bores formed intermediate "said body portion and said iiexible strip, cylindrical members releasably held within said bores and screws having threaded portions engaging in said cylindrical members and tapered heads engaging said body portion and said flexible strip.

5. In a reamer, a body portion provided with spaced radial slots, tapered ke s disposed within said slots and provide upon one side thereof with serrations, cutter members arranged within said slots and provided with serrations adapted to coact with the serrations in said keys, and means for locking said cutter members in position, em-

thereby forming intermediate said body porl tions and said first named slots flexible strips, cylindrical members releasably held Within bores formed partially in said Hex ible strips and partially in said body portion, means disposed within said first named bore for releasably engaging said cylindrical members and retaining them in position, and screws having threaded engagement with said cylindrical members and tapered heads engaging said body portion and said flexible strips.

ture.

EDWARD E. LARSON.

In testimony whereof I affix my signa-y 

